JPH02284800A - Automatic starting device for machine tool - Google Patents

Abstract

PURPOSE:To reduce the labor of an operator while securing safety by starting a machine tool after repeating cut-off light and passing light of beam of the light parting danger range by the planned times. CONSTITUTION:Flood lights 1 and light receivers 2 are set both right and left sides in front face of a press machine 5, respectively. The flood lights 1 and light receivers 2 are set at almost the same interval as the width size of the press machine 5 so as to cover the whole width of the press machine 5 with the beams of light on the plural optical axes 4. Then, by repeating the cut-off light and passing light of the beams of light on the optical axes 4 by the planned times in the planned time, it is detected that the setting of a work completes and the press machine 5 is started. On the other hand, at the time of cutting off the beam of light during operating the press machine 5, this is detected to stop the movement of the press machine 5. The starting and stopping timings of the press machine 5 are controlled with a control unit 3. Therefore, the operator can operate under devoting himself only to set the work to the prescribed position and take out the work after completing the machining.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an automatic starting device for a machine tool, and in particular, a dangerous area demarcated by light beams is provided in front of a machine tool such as a press machine. This invention relates to an automatic starting device for a machine tool that starts the machine tool when it is confirmed that the machine tool has not been erroneously touched.

(Prior Art) Machine tools such as press machines employ various automatic systems to perform efficient work.

For example, some machine tools are configured to automatically start up when it is detected that a workpiece is set on the machine tool. This allows the press work to be started without the operator having to operate the start switch each time, which has the advantage of reducing the labor of the operator.

(Problems to be Solved by the Invention) In the conventional device described above, although the operating procedure by the worker is simplified and the labor is reduced, once the workpiece is set at the machining position, it is automatically performed regardless of the worker's intention. Since the machine tool is started automatically, it is necessary to pay attention to safety, and there is a problem in that the psychological fatigue of the worker cannot be alleviated.

Because of these problems, there has been a demand for a device that is equipped with a safety device and that can automatically start the machine tool when a workpiece is set on the machine tool.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic starting device for a machine tool that solves the above-mentioned problems and can reduce the labor of the operator while ensuring safety.

(Means and Effects for Solving the Problems) In order to solve the above problems and achieve the objects, the present invention provides that the light beams that define the dangerous area around the machine tool are repeatedly blocked and passed a predetermined number of times. The present invention is characterized in that it is equipped with a counting means for detecting that the light has been blocked and a means for starting the machine tool after the light blocking and light passing have been repeated the predetermined number of times.

A second feature of the present invention is that it includes a timer means for clearing the count value of the counting means when the repetition of light blocking and light passing is not performed for a scheduled time.

In the present invention having the above configuration, it is detected that the workpiece is set on the machine tool based on the number of times the light beam is interrupted;
Further, the machine tool is activated after it is detected by the passing of the light beam that the operator's hand or the like is not inserted into the dangerous area.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 7 shows a perspective view of a press machine as an example of a machine tool equipped with the automatic starting device of the present invention.

In the figure, a light projector 1 and a light receiver 2 are arranged on both left and right sides of the front surface of the press machine 5, respectively. The light projector 31 has a plurality of light emitting elements, and the light receiver 2 has the same number of light receiving elements as the light emitting elements, which are arranged vertically and facing each other. The press machine 5 is arranged with an interval between the width dimension and the path so that the entire width of the press machine 5 is covered by the light beams on the plurality of optical axes 4 connecting the press machine 1 and the light receiver 2. .

When the light beam on the optical axis is repeatedly blocked and passed a predetermined number of times within a predetermined time, it is detected that setting of the workpiece is completed, and the press machine 5 is started.

On the other hand, if the light beam is blocked during operation of the press machine 5,
When this is detected, a clutch (not shown) that transmits the power of the prime mover to the press machine is disengaged, and the operation of the press machine 5 is suddenly stopped.

The start/stop timing of the press machine 5 is controlled by the control device 3.
controlled by

Next, the configuration and operation of the control device 3 will be explained. FIG. 1 is a block diagram showing the configuration of a control device.

In FIG. 1, a light projector 1 includes a light emitting diode device (hereinafter simply referred to as a light emitting diode) l-1.

1-2, .
,■- A phototransistor device (hereinafter simply referred to as a phototransistor) is placed on the optical axis opposite to n 2-
1.

2-2. ...12-n are arranged.

The synchronization signal generator 6 generates synchronization signals at scheduled intervals.

The selection signal generation section 9 outputs a scheduled optical axis selection signal to the optical axis data storage section 7, demultiplexer 8, data comparison section 10, and multiplexer 11 in response to this synchronization signal. This selection signal generating section 9 can be configured by a counter.

The optical axis data storage section 7 stores each of the light emitting diodes 1-1.
, 1-2, . . . , n types of optical axis data representing optical axis numbers corresponding to l-n (specific examples of optical axis data will be described later) are stored. Then, optical axis data corresponding to the optical axis selection signal is output from the optical axis data storage section 7 to the demultiplexer 8. The demultiplexer 8 is
the light emitting diode l selected according to the selection signal;
-1, 1-2, . . . , 1-n, the optical axis data is distributed and inputted. The light emitting diode to which the optical axis data is input outputs a digitally modulated optical signal based on this optical axis data.

Furthermore, the detection signal of any one of the phototransistors 2-1, 2-2, ..., 2-n% selected by the multiplexer 11 according to the selection signal output from the selection signal generator 9 is sent to the decoder 12. is input.

The detection signal decoded by the decoder 12 is input to the data comparison section 10 and compared with the optical axis selection signal input from the selection signal generation section 9 .

The data comparison section 10 compares the optical axis selection signal with the decoder 1.
2 does not match, it is determined that the optical axis to be detected among the optical axes formed between the emitter 1 and the light receiver 2 is interrupted, and an optical axis interruption signal is output. That is, the output signal a of the data comparator 10 becomes mH#.

The signal a is distributed by the press position determining section 16 and becomes a signal a1 inputted to the counting means 13 or a signal a2 inputted to the clutch driving section 15.

The press position determination unit 16 determines whether or not the press head (not shown) of the press machine 5 is at the top dead center based on the detection signal of the top dead center detection sensor 18, that is, the press head is located at the start preparation position. Based on the result of the judgment, the signal a is divided into al and a2.

When the press head is at the top dead center, the press position determining section 16 outputs a signal a1, and when the press head is at a position other than the top dead center, a signal a2 is output.

In the counting means 13, the output of the optical axis cutoff signal a1 is "H".
The count value is updated every time it changes from "L" to "L". When the count value of the counting means 13 reaches the predetermined number of times, the signal outputted from the counting means 13 to the monostable multivibrator (one-shot multi) 17 becomes "H". The signal input to the one-shot multi 17 is “H”
In other words, when the count value of the counting means 13 reaches the predetermined number of times and the signal becomes "H" and the optical axis cutoff signal a1 is in the "Lo" state, this one-shot multi 17
Clutch drive signal C is scheduled for the scheduled time (for example, 0.5 seconds)
is output.

The clutch drive unit 15 operates to connect the clutch that transmits the driving force from the drive source to the press machine 5 when the drive signal C is H''.

That is, after the light beam on the optical axis is repeatedly blocked and passed a predetermined number of times, it is transmitted from the counting means 13 to the clutch drive unit 1.
A drive signal C of "H" is output to the press machine 5, and the clutch for transmitting the drive force to the press machine 5 is connected.

When the press head of the press machine 5 is not at the top dead center, the output signal a of the data comparison section 10 is directly inputted to the clutch drive section 15 as a signal a1 via the press position judgment section 16, so that the optical axis As soon as the upper beam is interrupted, the press is brought to a sudden stop.

The timer means 19 starts counting time when the top dead center detection sensor 18 detects that the press head has returned to the top dead center. The count value of the counting means 13 is cleared by the reset signal d when the timer means 19 starts measuring time and when the scheduled time measurement ends.

In this way, the count value of the counting means 13 is determined by the timer means 19.
Since it is cleared every time the scheduled time is elapsed, even if the work is interrupted in the middle before the counted value of the counting means 13 reaches the scheduled number of times, the work can be resumed after the scheduled time has elapsed. The automatic startup device can be reliably started up from the initial state.

For example, if the scheduled number of times is set to 2, but the work is interrupted when the current count value is 1, when the work is resumed, only one light blocking/lighting is performed, which will affect the worker's intention. The press machine will start up without any warning, which may confuse the operator.

Even if the press machine were to start regardless of the worker's will, the press machine would suddenly stop under light-blocking conditions, so it would not cause any serious problems. The machine is ready to start.
This is more desirable for safety reasons.

The operation of this embodiment with the above configuration will be explained with reference to the flowchart of FIG.

In the figure, first, in step S7, the press position determining unit 16 determines whether the press head has returned to the top dead center position (starting preparation position), and if the determination here is affirmative, the process proceeds to step S8. .

In step S8, the count value of the counting means 13 is cleared to "0°."

In step S9, the timer means 19 starts measuring the scheduled time. In this embodiment, 5 seconds is set as an example of the scheduled time.

In Step SIO, all optical axes are scanned, and in Step Sll, presence or absence of blocking (light blocking) and non-blocking (light passing) of the light beam is detected, and if light blocking and subsequent light passing are detected, the count value is calculated. Add "1" (step 512).

In step S13, it is determined whether the counted value has reached the expected counted value. In this embodiment, this scheduled count value is set to 2 times. By setting 2 times as the planned count value, it is possible to cut the light once when the worker puts his/her hand into the dangerous area to take out the pressed workpiece. The point in time when light passes, and one time of light blocking and light passing when a hand is put into the danger area to set the next workpiece to be processed at a predetermined press position and the hand is removed from the danger area. It is possible to count the scheduled count value twice and output a count end signal.

Until the scheduled count value is counted, the process moves to step S18, and in step 318, it is determined whether or not the timer means 19 has timed up, that is, whether 5 seconds have elapsed.

If the timer means 19 has timed up, the process returns to the initial process; if the timer means 19 has not timed up, the process returns to step S10.

If it is determined in step S13 that the count value of the counting means 13 has reached the scheduled count value, the process proceeds to step S14, where the clutch drive signal C is output for a scheduled time (for example, about 0.5 seconds).

After outputting the clutch drive signal C, the process returns to the initial process, and it is determined again in step S7 whether or not the press head is at the top dead center position. Since the press head is lowered by the drive signal, the determination in step S7 is negative and the process proceeds to step S15.

In step S15, a normal light blocking/light passing check is performed on all optical axes, that is, on all optical axes.

At step 316, it is determined whether or not light is blocked depending on whether an optical axis blocking signal, which will be described later with reference to FIG. 6, is output. If at least one optical axis is cut off, a signal for disengaging the clutch is output from the clutch drive unit 15 in step S17.

If the light is not blocked, the process returns to the initial process, and unless the press head is located at the top dead center, the judgment in step S7 is negative, and the normal stop mode process in steps S15 to S17, that is, the light beam is blocked. If detected even once, the process of immediately stopping the press machine is repeated.

Next, a specific example of the optical axis data will be explained with reference to FIGS. 2 and 3.

As shown in FIG. 2, the optical axis data is data D.

The data D5 is constituted as one set. Furthermore, each of the data DO to D5 is formed using the waveform shown in FIG. 3(a) as a basic pulse, the pulse signal representing "0#" shown in FIG. 3(b), and the pulse signal representing "0#" shown in FIG. ) is assembled with a pulse signal representing "1" shown in FIG. 2. The data KO in FIG. This is a dummy signal.

Based on the combination of six pulse signals DO to D5 excluding the dummy signal KO, the light emitting diode l-
1, 1-2, . . . , 1-n can be digitally modulated, and a unique optical axis number can be added to each optical axis.

FIG. 4 shows an example of the combination of the optical axis number and the pulse signal. As shown in the figure, the optical axis numbers of 64 optical axes can be set using six pulse signals.

Next, the detailed flow of the all-optical axis scan in steps SIO and S15 will be explained according to the flowchart of FIG. 6.

In FIG. 6, first in step S1, in order to read optical axis data from the optical axis data storage section 7, "0" is set in the selection signal generating section 9 as the initial value of the optical axis number.

Next, in step S2, data (pulse signal) representing the optical axis number "θ" set in step S1 is sent from the optical axis data storage section 7 to the light emitting diode 1-1 via the demultiplexer 8.

The light emitting diode 1-1 outputs a digitally modulated optical signal based on this optical axis data.

In step S3, the decoder 12 determines whether the data received by the phototransistor 2-1 and the optical axis data representing the optical axis number "0" sent from the optical axis data storage section 7 match. The data comparison unit 10 makes a determination based on the decoded value and the optical axis selection number. If both data match, it is determined that the scheduled optical axis data has been detected, and the process proceeds to step S4.

In step S4, it is determined whether the optical axis data output in step S2 is optical axis data representing the final optical axis number.

If it is not the final optical axis, the process proceeds to step S5, where the optical axis number set in the selection signal generator 9 is incremented, and the process returns to step S2.

When the optical axis number is incremented, in the next process in step S2, optical axis data representing this incremented optical axis number is output.

On the other hand, if it is determined in step S4 that the optical axis data corresponding to the final optical axis number has been output, it is assumed that all optical axes have been detected and the process returns to the flow of FIG. 5.

Further, if the judgment in step S3 is negative, that is, the data received by the phototransistor 2-1 and the optical axis data representing the optical axis number "0" sent from the optical axis data storage section 7 match. If not, it is determined that the optical axis "0" is interrupted, and the process moves to step S6, where an optical axis interruption signal a is output.

As explained above, in this embodiment, when the press head is located at the top dead center, the downward movement of the press head is automatically started after light blocking and light passing are repeated a predetermined number of times. Ru.

On the other hand, if the press head is not located at the top dead center, the operation of the press head is controlled to stop immediately when the interruption of the optical axis is detected.

In this embodiment, the press head is configured to automatically start lowering operation when light blocking and light passing are repeated twice. This is adapted to work formats in which workpieces are manually set and taken out.

Unlike the above-mentioned operations, there is a type of press operation in which the workpiece is automatically removed from the press position by a separately provided removal device after the processing is completed. In such a case, since it is only necessary to manually set the workpiece in the press position, the counting means 13 is set so that the lowering operation of the press head is started when the light is blocked and passed once. It is sufficient to set the count value "1" to .

In addition, the count value set in the counting means 13 can be arbitrarily determined depending on the work type.

Similarly, the scheduled setting time of the timer means 19 can be arbitrarily determined.

In this embodiment, the blocking/transmission of a light beam to which optical axis data representing the optical axis number is added is detected. It may also be possible to detect blocking or passing of light by a light emitting means used in the device.

Furthermore, the present invention is not limited to the case where the emitter and the receiver are arranged separately on both sides of the machine tool, but the sensor that integrates the emitter and the receiver is arranged on one side of the machine tool. It is also possible to irradiate light from a projector onto reflective mirrors arranged to face each other, and detect whether the reflected light is blocked or transmitted.

It should be noted that the present invention can of course be applied to machine tools other than BUNOS machines.

(Effects of the Invention) As is clear from the explanations given below, according to the present invention, when the light rays that demarcate the dangerous area are blocked and transmitted a predetermined number of times, this is detected by the machine tool in step 1. can be started automatically.

Since the machine tool is automatically started on the assumption that the machining head (head of the press machine) of the machine tool is at a scheduled start-up preparation position such as top dead center, if the machining head is at a position other than the planned position, , a safety mechanism that gives priority to stopping is activated.

Therefore, the C5 operator places the workpiece in the predetermined position.
= L. Also, since the worker can concentrate on taking out the workpiece after machining, the mental burden on the worker can be reduced, and work safety can be improved.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing an example of the format of optical axis data, Fig. 3 is a diagram showing the waveform of optical axis data, and Fig. 4 is a diagram showing the optical axis number and optical axis data. 5 and 6 are flowcharts showing the operation of the embodiment, and FIG. 7 shows an example of the relationship between the axis data and the
=1 is a perspective view of the installed press machine. 1... Emitter, 2... Light receiver, 3... Control device,
4... Optical axis, 6... Synchronization signal generation section, 7... Optical axis data storage section, 8... Demultiplexer, 9... Selection signal generation section, 10... Data comparison section, 11... Multiplexer, 12... Decoder, 13... Counting means, 15 River clutch drive section, 16... Press position judgment section, 19... Timer means agent Patent attorney Michito Hiraki and 1 other person Figure 2 Figure 3 (b) (C) Figure 4 Figure Figure

Claims (3)

[Claims] (1) A dangerous area is provided that includes a plurality of light emitting elements and a light receiving element disposed on the optical axes of the light emitting elements, and a dangerous area is provided that partitions at least the front side of the machine tool by the plurality of optical axes, and the An automatic start device for a machine tool equipped with an optical safety device that outputs an optical axis cutoff signal when the light on the optical axis is cut off, is used to detect when the machining head of the machine tool is in the start preparation position. a sensor means for detecting; a means for scanning all of the plurality of optical axes and detecting the presence or absence of a blocked optical axis; a counting means for incrementing a count value when the blockage of at least one optical axis and the subsequent release of the blockage are detected once by the means for detecting the presence or absence of optical axis blockage; and a count value of the counting means is scheduled. An automatic starting device for a machine tool, comprising means for starting the machine tool when a value is reached. (2) The automatic starting device for a machine tool according to claim 1, further comprising timer means for clearing the counted value of the counting means when the counted value of the counting means is not updated for a scheduled time. (3) The automatic starting device for a machine tool according to claim 1 or 2, wherein the light beam on the optical axis is a light beam digitally modulated based on optical axis data indicating each optical axis number.